Take-up mechanisms for sewing machines



8, 1936. M. l.. WATERMAN 2,063,280

* TAKE-UP MECHANISMS FOR SEWING MACHINES Filed June 29, 1935 PatentedDec. 8, 1936 UNITED STATES PATENT OFFICE TAKE-UP MECHANISMS FOR SEWINGMAC The Singer Manufacturing Company, Elizabeth, N. J., a corporation ofNew Jersey Application June 29, 1935, Serial N0. 28,996

Claims.

This invention relates to improvements in thread take-up mechanisms forsewing machines and more particularly in needle-thread take-ups, theinvention having for its object to provide for ready manufacture of adurable thread take-up mechanism capable of efliciently meeting highspeed requirements of operation.

With the above and other objects in View, the invention comprises thedevices, combinations and arrangements of parts hereinafter described inconnection with the accompanying drawing which illustrates a preferredembodiment of the invention, from which the several features of theinvention and the advantages attained thereby will be readily understoodby those skilled in the art.

In the accompanying drawing, Fig. 1 is a front end elevation of thebracket-arm head and bedplate of a sewing machine containing theimproved needle-thread take-up mechanism. Fig. 2 represents a verticalsection of the bracket-arm head of the machine. Fig. 3 represents anenlarged vertical section of the universal-joint connections between thetake-up lever and its actuating crank-member. Fig. 4 represents ahorizontal section of the connections illustrated in Fig. 3. Fig. 5represents a perspective view of the pivot-block of the universal-jointconnection.

Referring to the drawing, the sewing machine frame includes the usualbed-plate or worksupport I and a bracket-arm terminating at its free endin a head 2 which overhangs the worksupport.

Rotatably journaled in the bracket-arm I is a horizontally disposedactuating shaft 3 carrying a counterweighted crank-arm 4 provided with acrank-pin 5. Pivotally embracing the crank-pin 5 is the upperbearing-boss B of a needle-bar link I having its lower bearing-boss 3pivotally embracing a stud-pin 9 extending from a split collar I0 whichis clamped upon the upper end of a needle-bar II. The needle-bar II isjournaled for vertical reciprocation in a bearing bushing I2 suitablysecured in the bracket-arm head 2, the needle-bar carrying at its lowerend a needle I3.

Cooperating with the needle I3, below the work-support I, is aloop-taker I4 which in the present instance is of the horizontal-axisrotary hook type adapted to cast loops of needle-thread about a mass ofunder thread contained in a bobbin-case I5.

The work is intermittently advanced by a dropfeed mechanism including afeed-dog I6 operating through the throat-plate I1 upon the worksupport.Yieldingly opposed to the feed-dog is a presser-foot I8 carried by theusual spring-aepressed presser-bar I9 vertically movable in thebracket-arm head 2.

The present invention resides more particularly in the needle-threadtake-up mechanism and while, in its preferred embodiment, it is in thenature of an improvement on the take-up forming the subject of the U. S.patent to W. F. Dial et al., No. 695,915, Mar. 25, 1902, it is to beunderstood that the invention, as defined by the appended claims, is notrestricted to the specific type of take-up herein described andillustrated in the accompanying drawing.

According to the present construction, the upper end of the needle-barlink 1 carries a bearing member in the form of an auxiliary bearing-bossadjacent and substantially parallel to the bearing-boss G of said link.Journaled in said bearing-boss 20, for pivotal and bodily endwisemovements therein, is a stud-pin 2| having a circular head 22, providinga shoulder 23 which serves to limit inward movement of ther stud-pin 2|.Embracing the stud-pin head 22 is a collar 24 provided withdiametrically alined apertures 25, said collar being xedly secured uponthe head 22 by a screw 26.

The stud-pin head 22 is diametrically provided with a guide-slotpresenting parallel side walls 21 confining therebetween a pivot-block28 having spherically rounded upper and lower ends 28 in engagement withthe collar 24. The pivot-block 28 is provided with a guide-aperture 29terminating in the spherical ends of said block and slidably receiving aguide-rod 30 passing through the collar apertures 25, said aperturesbeing slightly larger than the diameter of the guiderod to provide forand limit tilting movements of the pivot-block.

The guide-rod 30 constitutes the depending arm of a two-armed take-uplever, of which the other arm 3I extends forwardly through a suitableslot in the bracket-arm head2 and adjacent to the usual guard-flange 32,the arm 3| of said lever being provided with the usual threadeye 33.Intermediate the arms 3D and 3l thereof, the take-up lever has a bearinghub 34 pivotally journaled upon a headed fulcrum-pin 35 disposedsubstantially parallel to the rotation axis of the actuating shaft 3 andto the pivotal axes afforded by the crank-pin 5 and the stud-pin 2|. Thefulcrum-pin 35 is suitably secured in an aperture in the frame head 2 bymeans of a set-screw 36. The take-up lever performs its usual functiono1' controlling the needle-thread in the formation md `setting ofstitches.

One of the outstanding problems in the sewing machine art has been theprovision of an efcient take-up mechanism capable of withstanding thewear incidental to operation of a. sewing machine at a speed at leastequal to 4000 stitches per minute. The crank-and-link type of takeuppresents lubrication diiii'culties, because of the bodily travel of theactuating connections for the take-up lever and the fact that an excessof lubricant may lead to soiling of the thread or the work. The presentinvention minimizes excessive lubrication requirementsbythe eliminationof undesirable cramped conditions infthe actuating connections for thetake-up lever, which cramped conditions mayarise fromV slightvariationsfrom true parallel relationshipofl the -axes 3, 5, 2| and 35, and fromany departures from the correct angular relationship "between the axis2| and the guide-rod 30. I Y

According to the present invention, the tiltable l.pivot-.block..28 andthe pivotal connection between ...the bearing-bossi() 4and the stud-pin2|, comprise universal-joint connections with the ltake-up` lever-whicheliminate the extreme precision require- :ments-diflicult tofmaintainunder mass produc- .tion. As the `axis 35 of the take-up lever is fixed,intherpresent arrangement, the take-up lever 30, v.3|.fvibrates in`asingle plane. VShould the axis of thetakc-up lever-L30, 3| benot inperfect parallelism withY the axis of.` its .actuating crank-mem- ,.ber,the, planeV4 of vibration of the take-up lever ,will be slightlyinclined to the-horizontal axis of the shaft 3. To accommodate .thiscondition, the stud-pinZl isf-ree tomove endwise inthe cranknbearing-boss `20. Thus, the take-up lever acituating vconnectionsautomatically assume free .t driving relations and. therefore mayoperate with fa minimum offrictionv and consequent minimum heating yandwear at high speed operation.

,Having thusfset. forth the nature of the invenition,Y whatIfclaimherein is:-

i ,1. Thread take-up mechanism for sewing ma- ..chines comprising, .apivotally mounted take-up `lever,..and supporting and actuating meansfor said leverincluding acrank-member, a connection-element freelymovable in a direction subestantially ,parallel `to the turning axis ofsaid crank-.memberr and a universal-joint connection incorporated insaid means.

`2. Thread takeup mechanism for sewing machinescomprising, a take-uplever, andsupportingand, actuating means for said take-up leverincluding av crank-member, and relatively trans- .versely pivotedconnections incorporated-in said Ymeans.

I3. Thread take-.up mechanism for sewing kmachinescomprising, a`take-uplevenrand support- Ving and actuating means forsaid take-.uplever including a v.connection-.element freelyA movable endwise, andrelatively transversely pivoted connectionsV incorporated in said means.

.4. Threadtake-up mechanism forsewing machines comprising, avpivotallymounted take-up lever provided with a thread-eye, a rotary crankmember,a pivot-block in sliding engagement with said take-up lever, andrelatively transversely pivoted connections between said crank-memberand pivot-block.

5. Thread take-up mechanism for sewing machines comprising, a pivotallymounted take-up lever provided with a thread-eye and having a guide-rod,a. rotary crank including a pivotal and endwise movableconnection-element and a pivot-block in sliding engagement with saidguiderod and fulcrumed upon said connection-element for.. pivotalmovement about an axis transverse to the pivotal axis of theconnection-element.

6. Thread take-up mechanism for sewing machines comprising, a pivotallymounted take-up lever, a connection-element provided with a guide-slot,a pivot-block tiltably disposed in said guide-slot and slidably engagingsaid take-up lever, and a bodily rotatable support for saidconnection-element providing for pivotal and bodily endwise movementsthereof.

7. Thread take-up mechanism for sewing machines comprising, a rotarycrank-pin, a bearing member pivotally carried by said crank-pin, a

-stud-pin-supported by said bearing member for pivotal and bodilyendwise movements, a pivotblock fulcrumed upon said stud-pin for pivotalmovement about an axis transverse to the pivotal axis of the stud-pin, atake-up lever provided withr a thread-eye and having an arm slidablyengaged by said pivot-block, and a pivotal support for-said take-uplever.

8. Thread take-up mechanism for sewing machines comprising, a rotarycrank-pin, a bearingmember pivotally carried by said crank-pin, lastud-pin supported by said bearing-member-for pivotal and bodily endwisemovements, said studpin havinga head provided with a guide-slot, an

apertured pivot-block` tiltably disposed in the guide-slot of thestud-pin head and fulcrumed upon said head for pivotal movement about anaxis transverse to the pivotal axis of said studpin, a take-upleverprovided with a thread-eye and having an arm slidably embraced bysaid pivot-block, a pivotal support for said take-up lever, and meanscarried by said stud-pin head for limiting tilting movement of saidpivot-block.

9. Thread take-up mechanism for sewing machines, comprising a pivotallymounted take-up lever having a guide-rod arm, a guide memberslidably-embracing said arm, a crank member, and universally jointedconnections between said `crank and guide members.

10. Thread take-up mechanism for sewing machines,.comprising a pivotallymounted take-up `lever having a guide-rod arm, a guide member slidablyembracing said arm, a crank member having a turning axis substantiallyparallel to the pivotal axis ofthe take-up lever, and universallyjointed connections between said crank and guide members.

MAX L. WATERMAN.

